EC 3749 then IB 5420 at Barcelona
Milan → Barcelona → London Gatwick
Timetable, Barcelona time
21:30EC 3749 from Milan at the gate
18:10IB 5420 to London Gatwick leaves the gatealso LL 5420, VY 7624, BA 8078
20 h 40 apart on the timetable, overnight
IB 5420 leaves 20 h 40 after EC 3749 arrives on the timetable: more than half a day, so not a connection we count.